Test Coverage Skill

Analyze test coverage and generate missing tests to reach 80%+ coverage.

Workflow

1. Run tests with coverage reporting
2. Analyze coverage report
3. Identify files below 80% threshold
4. For each under-covered file:
   • Analyze untested code paths
   • Generate unit tests for functions
   • Generate integration tests for APIs
   • Generate E2E tests for critical flows
5. Verify new tests pass
6. Show before/after coverage metrics

Focus Areas

• Happy path scenarios
• Error handling paths
• Edge cases (null, undefined, empty, boundary values)
• Branch coverage (if/else, switch cases)

Coverage Commands

JavaScript/TypeScript

npm test -- --coverage
pnpm test -- --coverage

Go

go test -cover ./...
go test -coverprofile=coverage.out ./...
go tool cover -func=coverage.out

Python

pytest --cov=. --cov-report=term-missing

Coverage Targets

Code Type	Target
Critical business logic	100%
Public APIs	90%+
General code	80%+
Generated/vendor code	Exclude